This page lists bugs in the original (Knuthian) TeX distribution which have been received since the last tune-up (2021). They have been accepted by Knuth's vetters, but are not expected to be seen by Knuth until the next tune-up. The original reports and answers have been edited or paraphrased for presentation here, and anonymized unless the reporter preferred to be named.
The page and module numbers are just an initial hint about a relevant location; typically more than one place in the code is involved. The initial letter (A, B, …) refers to the Computers & Typesetting volume.
A list of non-bugs is also available. These plausible reports have already been deemed not a bug by Knuth or his vetters.
For any discussion about these issues, or further reports, please use the contact information on the main TeX bugs page here.
A143,A152 2021-01-20: The descriptions of \above and \abovewithdelims don't mention that the given <dimen> affects the spacing above and below the fraction rule, as well as specifying the height of the rule. Appendix G rule 15d gives the computation, but the visual effect is hard to infer. Indeed, the typeset results are undesirable for any <dimen> larger than 1pt or so; the fraction appears too spacey (but of course the behavior cannot be changed at this late date).
A332, line 14 2021-02-26, Wolfgang Helbig: Replace "exercuted" by "executed". [Typo made in a correction in 2017.]
C210, line -13 2021-02-14: The implication is that the <argument>s in the syntaxes of Chapter 25 stand for "expr" arguments, but they actually stand for arguments of any kind. Knuth added a <future pen argument> in the 2021 tuneup, so he clearly had arguments of any kind (primary/secondary/tertiary/expr/to a for loop/etc.) in his mind.